1. Field of the Invention
The present invention relates to a rendering system that renders (i.e., performs raster image processing (RIP) on) an object, a method for optimizing data, and a storage medium.
2. Description of the Related Art
Currently, it has become common to upload digital data in commercial printing services, such as printing of catalogues, pamphlets and advertisements, due to the development and spread of digitization and networks. Further, such use of digital data has lead to a spread of on-demand printing in which printing is performed as necessary when necessary. The digital commercial printing service is thus required to perform high-quality printing in a short time, so that high-speed and high quality printers are used in a system, or a plurality of servers are used to perform distributed processing.
The uploaded digital data employs PostScript or Portable Document Format (PDF) as a printing format. When such printing formats are employed, it becomes necessary to render (i.e., perform RIP on) the digital data by page. A plurality of server computers which performs rendering is thus used, or the pages are previously rendered by multithreading the process or performing multiprocessing, to distribute the processing load and thus realize high-speed printing. Furthermore, PDF/variable and transactional (VT) format which has been standardized in September 2007 is expected to be widely used as a printing format.
When such printing formats are employed, the rendering process cannot be divided by page in a case where there is an object that is commonly referred to by a plurality of pages, even when a plurality of rendering server computers is used. As a result, the digital data is transmitted to the rendering server computers in files instead of dividing by page, and the rendering server computer renders only the necessary page.
Japanese Patent Application Laid-Open No. 2005-149347 discusses a technique for distributing the printing load. Such a technique accumulates data on a time for which rendering has been performed in the past, then estimates a time for which rendering is to be performed when performing the subsequent rendering process, and distributes the rendering process. Further, Japanese Patent Application Laid-Open No. 2007-213234 discusses a method for performing the rendering process using a plurality of rendering server computers, so that each rendering server computer performs rendering in an ascending order or a descending order of pages.
Conventionally, high-speed rendering (RIP) has been developed to shorten the printing time. However, there has only been a focus on speeding up the rendering process, so that the speed of processing performed before the rendering process has not been increased. Further, since the print data cannot be divided by page, the print data is transmitted to all rendering server computers in files even when the system includes a plurality of rendering server computers. Each of the rendering server computers thus individually renders the object that is commonly referred to by the pages, so that the rendering server computers redundantly perform the same process with respect to the common object.